Fixing a spoke…

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  • #971983
    Dirt
    Participant

    On the rear wheel, you’ll probably need to remove the cogs and chain whip, as you said. If you’re not going to be doing this often, I’d suggest going as inexpensive as possible. Many shops have a Park tool stand and you can just find what you need there. A shop jock can help you find the right stuff.

    Removing and cleaning the cogs is a great thing to do yourself. It isn’t difficult and it pays dividends in better shifting.

    When it comes to threading the spoke, look carefully at how the broken one is threaded in. You’ll need to put the new one in using the same pattern. The spokes cross and weave between each other. Most common pattern on 32 spoke wheels is what they call 3-cross. That means each spoke crosses three other spokes (on the same side of the wheel) between the hub and the rim. The spoke will go over two, then under one before getting to the nipple.

    You’ll need to get the correct length replacement spoke. It is good to buy a few spares if you’re the kind of person who saves things. There are numerous spoke calculators on-line. I’ve been using Pro Wheel Builder’s calculator with good results lately: http://www.prowheelbuilder.com/spokelengthcalculator/

    One more thing when you’re doing this… when you take the cogs off, look carefully at the spokes behind them. If you’ve dropped the chain off the top of the cogs a few times, you’ll see that these spokes get quite chewed up. If they are chewed up and your spoke broke here, then you’ll really need to have the whole wheel rebuilt. It is only a matter of time before more spokes break.

    One more, one more thing: (I lied about the last “one more thing” comment): Once you’ve replaced the spoke and tightened it up similar to what the others around it, you’re still going to need to true the wheel. Just replacing a spoke will not completely make the wheel true. The act of a spoke breaking impacts every other spoke on the wheel and it takes at least a little effort to get it all straight again. There are good how2s for wheel truing out there…. Lennard Zinn’s books are pretty good. I think Sheldon Brown (MHRIP) has good info on the process. Lots of folks love Jobst Brandt’s bicycle wheel book.

    ljksdfoui

    Sorry. That was Mao! helping me type.

    Truing the wheel can be done using the brakes as guides, but a truing stand really does the job right.

    Okay, I think that covers most of it. Let me know how else I can help.

    Pete

    #971984
    DismalScientist
    Participant

    Sure, you should try it yourself. What’s the worse thing that could happen?:rolleyes: (You can always bring the results of your “repairs” to the LBS.

    If you can do this, you can also replace the chain and cassette when that time comes.

    Brand names don’t matter when it comes to cassette removal tools and chain whips. I would suggest a box wrench that fits your cassette removal tool. You will need a spoke wrench as well. You might as well get the chain tool as well.

    Use the brake pads as a guide when truing the wheel after replacing the spoke–no need for a truing jig.

    #971985
    jabberwocky
    Participant

    @ebubar 54151 wrote:

    Would the bike gurus on here recommend me trying such a fix myself?

    Sure. Removing and installing a cassette is dead simple. I like the Park tools, but you don’t need to be ultra picky. You need a lockring tool, a chainwhip and a wrench to turn the lockring with.

    Replacing the spoke isn’t complicated either, though it requires a little more finesse to get the wheel true (though losing one spoke on a 32 spoke wheel probably didn’t throw the wheel too out of wack). Remove cassette, thread the spoke through paying attention to how it should go (under or over the other spokes). Thread it into the nipple. Tighten the nipple with a spoke wrench. Once it has some tension, check the trueness; the amount of tension in the spoke will pull the rim to the side it angles towards.

    #971992
    ebubar
    Participant

    You’ve inspired me to give it a go. Perhaps I can get to the bike shop tonight before close and get everything I need.
    Drive my wife insane by working on my bike in the late evening hours!

    #971994
    rcannon100
    Participant

    If this is your first time doing this stuff, consider going to a bike COOP – using their stuff, and getting “help” from the staff. I went to Velocity when I was having trouble with my derailer. They were GREAT!!! If there is a COOP near by, it might be a good alternative to buying all these tools.

    #971996
    Jason B
    Participant

    too bad you’re not on this side, I’d tell you to head over to VeloCity Bike Co-op in Del Rey. They would let you use the tools and walk you through the entire process for a small donation. Heck, they probably have a used spoke for a nickel. Takoma is pretty hippy, isn’t there a similar bike cooperative over there?
    Also, when you take off that cassette, zip tie the whole thing. Can’t tell you how many spacers I’ve lost!

    #971998
    hozn
    Participant

    The zip tie is a great suggestion. The only other thing that I’d add is some emphasis on making small adjustments to spoke nipples — like 1/4 turns then evaluate the effect. The “worst thing that can happen” here is that you could bend your rim out of shape by over-zealous tightening at which point you will need a lot more than a new spoke. (I figure it’s worth a mention, because this happened to my sister a few years back when she decided to replace a spoke and didn’t quite realize that truing wheels is best approached with restraint.)

    #971999
    jopamora
    Participant

    Take thee to the Bike House on Saturday at noon.

    #971991
    Bilsko
    Participant

    to add to your purchase list:
    New rim tape for when you’re all done with spoke replacement and truing
    –Advice from a guy who’s only ever taped a rim once, ever. (Extra ‘ever’ for emphasis.)

    #972012
    baiskeli
    Participant

    Just to add:

    The cassette remover depends on the type of cassette. They aren’t all the same. Remember to get one to match.

    The cassette side will have different spoke length than the others, so don’t forget that when you shop. The other side on the rear tire may be a different length than the front ones too, for future reference.

    #972013
    krazygl00
    Participant

    @hozn 54178 wrote:

    The zip tie is a great suggestion. The only other thing that I’d add is some emphasis on making small adjustments to spoke nipples — like 1/4 turns then evaluate the effect. The “worst thing that can happen” here is that you could bend your rim out of shape by over-zealous tightening at which point you will need a lot more than a new spoke. (I figure it’s worth a mention, because this happened to my sister a few years back when she decided to replace a spoke and didn’t quite realize that truing wheels is best approached with restraint.)

    Yep. In truing, “less is more”. In this case what you should do is pretty straightforward. Tighten the new spoke very small amounts until the wheel approaches true, then stop. Don’t touch any other spokes, just get the wheel to a shop where they can do a final truing. Also, be sure to mark the new spoke with electrical tape or something. If you want it done properly, the new spoke needs to be pre-tensioned just as the other spokes are, then re-trued and finally the wheel probably ought to have a good going-over with a tensiometer.

    @Bilsko 54187 wrote:

    to add to your purchase list:
    New rim tape for when you’re all done with spoke replacement and truing
    –Advice from a guy who’s only ever taped a rim once, ever. (Extra ‘ever’ for emphasis.)

    Rim tape is totally re-useable! I’ve done this countless times. As long as it sticks well enough to get the tire and tube on and there are no holes you’re good to go. I’ve even transplanted old rim tape from a retired wheel to a new one (provided the width was the same).

    #972015
    jabberwocky
    Participant

    I can generally replace a spoke without having to remove the rim tape (or even the tire), as long as the old spoke is still there and the nipple hasn’t fallen into the rim. Just be careful removing the old spoke remnant and threading the new one on.

    #972018
    ebubar
    Participant

    I’ve got pictures of the spoke so I can rethread it correctly. I suspect the following should be good for cassette removal: http://www.parktool.com/product/cassette-lockring-tool-fr-5

    Its a stock trek 7.2 fx so the cassette is shimano branded as far as I know. Seems like a regular old chain whip should work fine too (http://www.parktool.com/product/sprocket-remover-chain-whip-sr-1).

    I imagine (perhaps wrongly) that a pretty standard stock bike should use more or less standard stock tools. If I knew enough to have something fancier, then I would probably know of any
    special or “fancy” tools that I needed.

    If I try to hitup the LBS tonight after departing metro (without a bike in hand), can I just tell them “I need a cassette removal tool for a Shimano rear cassette and a chain whip” and they
    should know what i’m talking about?

    Then over to Ace hardware for a long adjustable wrench (i’m imagining I’ll need a goodly amount of torque) and I should be good to go!

    #972019
    krazygl00
    Participant

    @ebubar 54200 wrote:

    Then over to Ace hardware for a long adjustable wrench (i’m imagining I’ll need a goodly amount of torque) and I should be good to go!

    If you have a bench-mounted vice you should be able to forgo the large wrench. Drop the lockring tool into the vice, attach the chain whip to the cassette, then drop the cassette onto the lockring tool and remove. Installation is easy; you just use the wheel to torque the lockring back on.

    #972027
    baiskeli
    Participant

    @ebubar 54200 wrote:

    If I try to hitup the LBS tonight after departing metro (without a bike in hand), can I just tell them “I need a cassette removal tool for a Shimano rear cassette and a chain whip” and they should know what i’m talking about?

    Not quite. This article shows several cassette tool types, including two different Shimano types.

    http://www.parktool.com/blog/repair-help/cassette-and-freewheel-removal (scroll down)

    One of them is probably more common though – perhaps common enough to just buy it and try it. The shop may know.

    The article above should be useful to you in general too.

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